1. Field of the Invention
The present invention relates to poles and more specifically relates to poles formed from modular components made of a composite material.
2. Description of the Related Art
The electric utility distribution pole market is dominated by standard, treated wood poles furnished by hundreds of wood preserving plants located throughout the United States. While relatively inexpensive in initial cost, wood poles face several issues ranging from the chemical preservatives with which they are treated to the structural soundness of newer poles.
The wood treating industry comes under ever increasing attack from environmentalists and other public interest groups based on claims that the chemical preservatives used in the treatment of wood poles, which include a large quantity of pesticides, may cause public health problems.
New poles are often constructed from “new growth” forests, which consist primarily of fast-growing hybrid species of trees. Some claim that the faster growing species may not be as strong as trees that are cultivated over many years from virgin forests.
To address these issues, as well as to provide a more aesthetically-pleasing utility pole, poles have been developed from various metals and composites in a variety of structural assemblages.
Prior art utility poles include:
U.S. Pat. No. 466,012 issued to J. S. Seaman on Dec. 29, 1891, discloses a method for the manufacture of posts and poles utilizing welding as a joining process for the steel plates comprising the improved post and poles.
U.S. Pat. No. 999,267 issued to E. E. Slick on Aug. 1, 1911, discloses a method of making tapering metal poles. This invention eliminates the requirements of inner webbing and a nested section required for vertical strength. The invention does not utilize mechanical bolting or welding as a means of fastening. The invention utilizes rolled blanks forming interlocking edges running vertically such that the rolled sections may be assembled.
U.S. Pat. No. 3,196,990 issued to H. E. Handley on Jul. 27, 1965, discloses a tapered structural member and method of making same. This invention utilizes aluminum as the preferred material and incorporates welding as a method of fastening longitudinal peripheral portions.
U.S. Pat. No. 3,276,182 issued to H. E. Handley on Oct. 4, 1966, discloses a taper structural member constructed from sectional vertical members coupled by tongue and groove fits. Internal bolting prevents rotation about the long axis of the vertical member.
U.S. Pat. No. 3,291,437 issued to G. F. Bowden et al. on Dec. 13, 1966, discloses a flexible panel with abutting reaction shoulders under compression for use in a vertical load-bearing member.
U.S. Pat. No. 3,557,422 issued to H. C. Pfaff, Jr. on Jan. 26, 1971, discloses a method of forming a pole base structure consisting of slotted panels arranged in a geometrically stable pattern. Each panel consists of a crimped edge, which is designed to be inserted into the slotted portions of the panels.
U.S. Pat. No. 3,571,991 issued to Edward S. Doocy et al. on Mar. 23, 1971, discloses a tubular steel pole with pairs of sidebars and web members secured together by welds along the edges of the sidebars. Internal bracing exists at points where sidebars extend outward.
U.S. Pat. No. 4,312,162 issued to Jonas Medney on Jan. 26, 1982, discloses a reinforced fiberglass pole suited for use in electric transmission systems. The invention utilizes reinforcing regions consisting of composite material made from pre-stressed longitudinally disposed fibers.
U.S. Pat. No. 5,285,613 issued to W. Brandt Goldsworthy et al. on Feb. 15, 1994, discloses a pultruded joint system and tower structure including re-entrant slots which lock into place horizontal members used to support a vertical load.
U.S. Pat. No. 5,319,901 issued to Goldsworthy et al. on Jun. 14, 1994, discloses a technique for connecting a cross member brace between a column and another cross member. A dovetailed shoulder fit facilitates the interlocking connection.
U.S. Pat. No. 5,617,692 issued to Johnson et al. on Apr. 8, 1997, discloses composite structure made entirely from interlocking pultruded composite members. The interlocking members found in this invention are non vertical strengthening members locate to give the vertical structure rigidity.
U.S. Pat. No. 5,644,888 issued to David W. Johnson on Jul. 8, 1997, discloses a heavy construction system using composite members, which are interfit using a dovetailed shoulder fit with other composite members to form a rigid post and beam or beam and brace.
U.S. Pat. No. 5,864,998 issued to Weston R. Loomer on Feb. 2, 1999, discloses modular structure members disposed in adjacent co-acting positions so that a selected number of modules assembled together form a peripherally enclosed modular structural member.
U.S. Pat. No. 6,094,881 issued to William D. Lockwood on Aug. 1, 2000, discloses a modular fiberglass reinforced polymer pole system comprising at least two corner pieces, each corner piece having two ends, and having a continuous channel and further comprising at least two tapered panel pieces, each panel piece designed to be glued into the slot of corner piece when said panel piece is fully inserted into said corner slot.
U.S. Pat. No. 6,286,281 issued to David W. Johnson on Sep. 11, 2001, discloses a tubular tapered composite pole for supporting utility lines formed from elongated panels made of pultruded composite material. The elongated panels are trapezoidal in shape featuring a tongue and groove fit along its mating surface with the adjacent elongated panel. The panels interlock to form a closed loop giving the vertical pole rigidity.
It would be an improvement in the art to have a pole that meets utility pole structural standards and that does not require treatment with pesticides and other potentially harmful chemical preservatives.
It would further be an improvement in the art to have a modular configuration that simply and easily allows for additional reinforcement pursuant to calculated strength desired.
It would further be an improvement in the art to have a modular fiberglass reinforced polymer pole, the components of which are easily packaged and shipped, and that may be simply assembled on or near the installation site rather than as a final product.
It would further be an improvement in the art to have a modular pole in which the interface of the modular components provides additional strength to the pole.